Habitat

Ruddy Ducks breed in wetlands and reservoirs from southwestern Canada through the western United States and Mexico, as well as in scattered sites in the eastern United States and on the Caribbean islands. About 86 percent of the breeding population is concentrated in the prairie pothole region of south-central Canada and north-central United States. Their breeding habitat includes large marshes, stock ponds, reservoirs, and deep natural basins. Migrating Ruddy Ducks stop in a variety of habitats, most often on large, permanent wetlands, lakes, and reservoirs. They spend the winter throughout the southern half of the breeding range, also moving into wintering habitat that spans most of the United States and extends through Mexico to Central America. Their wintering habitat includes freshwater wetlands, lakes, and reservoirs as well as brackish bays, coastal marshes, and tidal estuaries.Back to top

Food

Both adults and ducklings eat aquatic insects, crustaceans, zooplankton, and other invertebrates, along with small amounts of aquatic plants and seeds. They forage mostly by diving to the bottom of shallow ponds, straining mouthfuls of mud through thin plates on their bills and swallowing the prey items that are left behind. Occasionally they strain food from the surface of the water. Midge larvae form a large part of their diet. Other food items include water fleas, worms, amphipods, seed shrimp, snails, caddisfly larvae, dragonfly nymphs, predaceous diving beetles and their larvae, bugs, water boatmen, brine fly larvae, crane fly larvae, mosquitoes, mayflies, and plant material from arrowhead, pondweed, muskgrass, bulrushes, bayberry, spikerushes, water lilies, duckweed, and more. Plant material is more common in their diet during migration and winter than during the breeding season.Back to top

Nesting

Nest Placement

Usually placed 2–10 inches over the water in cattails, bulrushes, or grasses, the nest is supported and well-concealed by vegetation. The female chooses the site.

Nest Description

The nest is usually made of dead, dry plant materials, though some are built entirely with green vegetation. It starts as a platform and becomes more bowl-like throughout the construction process, with an inner cup measuring 4–12 inches across and 0.5–5 inches deep. Ruddy Ducks usually weave a canopy of vegetation over their nests.

Nesting Facts

Clutch Size:

3-13 eggs

Number of Broods:

1-2 broods

Egg Length:

2.3-2.7 in (5.9-6.8 cm)

Egg Width:

1.7-1.9 in (4.3-4.8 cm)

Incubation Period:

20-26 days

Nestling Period:

1 day

Egg Description:

White to yellowish white, with a pebbly texture.

Condition at Hatching:

Active, well-developed, and covered with down (dark above and lighter below).

Behavior

Ruddy Ducks spend the vast majority of their time on the water. They are fast fliers but have little maneuverability in the air, and they tend to swim and dive rather than fly to escape predators—which include Red-tailed Hawks, Great Horned Owls, mink, raccoons, and red foxes. Ruddy Ducks are very aggressive toward each other and toward other species, especially during the breeding season. Unlike most ducks, they form pairs only after arriving on the breeding grounds each year. Males perform unusual courtship displays in which they stick their tails straight up while striking their bills against their inflated necks, creating bubbles in the water as air is forced from their feathers. They punctuate the end of the display with a belch-like call. Courting males also lower their tails and run across the water, making popping sounds with their feet. Most males pair up with one female each for the duration of the breeding season, but some take multiple mates. Their eggs are proportionally the largest of all waterfowl. The ducklings hatch well-developed and active, receiving minimal care from the mother and none from the father. Ducklings are preyed upon by Black-crowned Night-Herons, Ring-billed Gulls, California Gulls, mink, and raccoons. Back to top

Conservation

Ruddy Duck populations were stable across North America from 1966 to 2014, according to the North American Breeding Bird Survey. Ruddy Duck is not on the 2014 State of the Birds Watch List. They can be found throughout the year in the U.S. and Mexico, and during the breeding season in Canada. Though they were hunted during the 1890s (and numbers probably declined during that time), they are not popular with hunters today. The U.S. Fish and Wildlife Service records about 50,000 Ruddy Ducks shot by hunters each year. Like all waterfowl, Ruddy Ducks are susceptible to poor water quality, pollution, and oil spills. The population in Chesapeake Bay dropped significantly between 1955 and 1979, probably because of habitat degradation from exotic species invasion and pollution. Ruddy Ducks depend heavily on wetlands in the prairie pothole region of North America, where grazing, burning, and wetland drainage have degraded portions of their habitat. Their future success will depend in large part on the protection and restoration of that region.Back to top